Research of power down-rejoining on control system for permanent magnet synchronous motor used in traction engines

A closed-loop transient optimizing control system was investigated in this paper, to reduce the current and torque impacts of permanent magnet synchronous motor used in traction engines when passing split-phase insulator and rejoining on power with a high speed. Firstly, this paper analyzed the impact cause when power down-rejoining on based on transient mathematical model of PMSM, considering the influence factors of the harmonic part of PWM modulation and fundamental sine voltage. Accordingly, a special value was found for the power rejoining on given speed of the closed-loop control system. For the power rejoining on position, there was a real-time correction and compensation. The concept of analog inverter was introduced to reduce momentary mechanical shock caused by mechanical switch when power down-rejoining on. Lastly, this paper designed an optimization controller which had the functions of real-time monitoring, parameter correction and final decision. The experiments and simulations verified the designed rejoining on optimizing control system.